How this calculator works
This tool first estimates your basal metabolic rate (BMR) — the calories your body burns at complete rest — using the Mifflin-St Jeor equation, which research has found to be among the most reliable formulas for most adults:
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Your BMR is then multiplied by an activity factor to estimate your total daily energy expenditure (TDEE) — the full number of calories you burn in a typical day, including movement and exercise.
Calories for weight loss and gain
Body weight responds to sustained energy balance. Eating roughly 500 kcal below your maintenance level is commonly associated with losing about 0.5 kg (1 lb) per week, while 500 kcal above supports a similar rate of gain. The milder ±250 kcal targets are slower but often easier to stick to — and consistency matters more than speed.
Avoid very low intakes: prolonged eating far below your needs can cause muscle loss, nutrient deficiencies, and rebound weight gain. As a general guide, most adults should not eat below their BMR for extended periods without medical supervision.
Activity level: be honest
| Level | Multiplier | Typical description |
|---|---|---|
| Sedentary | 1.2 | Desk job, little exercise |
| Lightly active | 1.375 | Exercise 1–3 days/week |
| Moderately active | 1.55 | Exercise 3–5 days/week |
| Very active | 1.725 | Hard exercise 6–7 days/week |
| Extra active | 1.9 | Physical job plus hard training |
Most people overestimate their activity level. If you sit most of the day and train three times a week, "lightly active" is usually closer to reality than "moderately active".
Calories in everyday foods
Numbers only become useful when you can picture them on a plate. Approximate values for common foods:
| Food | Serving | Calories |
|---|---|---|
| Cooked rice | 1 cup | ≈ 205 |
| Small flour tortilla | 1 medium | ≈ 100 |
| Boiled egg | 1 large | ≈ 78 |
| Banana | 1 medium | ≈ 105 |
| Apple | 1 medium | ≈ 95 |
| Cooked chicken breast | 100 g | ≈ 165 |
| Milk (whole) | 1 cup | ≈ 150 |
| Yogurt (plain) | 1 cup | ≈ 150 |
| Butter | 1 tbsp | ≈ 100 |
| Cheeseburger (fast food) | 1 medium | ≈ 360 |
| Pizza | 1 slice | ≈ 285 |
| Cola (regular) | 330 ml can | ≈ 140 |
Calories burned by common activities
Approximate energy burned per hour for a 70 kg (155 lb) adult — heavier bodies burn more, lighter bodies less:
| Activity (1 hour) | Calories burned |
|---|---|
| Walking (5 km/h) | ≈ 280 |
| Yoga | ≈ 240 |
| Cycling (moderate) | ≈ 560 |
| Swimming (moderate) | ≈ 500 |
| Running (8 km/h) | ≈ 600 |
| Strength training | ≈ 340 |
| Dancing | ≈ 330 |
| Household chores | ≈ 200 |
Where food calories come from
| Component | Calories per gram |
|---|---|
| Fat | 9 |
| Alcohol | 7 |
| Protein | 4 |
| Carbohydrate | 4 |
| Fibre | ≈ 2 |
This is why fatty foods are so calorie-dense, and why high-fibre, high-protein meals keep you fuller for the same calories. To split your daily target across these, use the macro calculator.
Related tools
Not sure where your weight currently stands? Check your BMI first. Once you have a calorie target, a macro calculator can help you split it into protein, carbs, and fat.
Practical guide for using this result
How the estimate should be used
Start near the maintenance value, then choose a modest deficit or surplus that still supports normal energy, sleep and training.
How to calibrate it
Compare the planned intake with two to four weeks of consistent weigh-ins. If the trend is faster or slower than intended, adjust gradually rather than making a large jump.
Why food quality still matters
Two diets with the same calories can differ greatly in protein, fibre, micronutrients, fullness and cardiometabolic impact.
How to turn a calorie estimate into a workable plan
A calculated target is a starting estimate. Your real maintenance level becomes clearer after two to four weeks of consistent intake and body-weight tracking.
Start near the estimate
Use the suggested calories without making extreme cuts. Keep meal structure, protein and fibre reasonably consistent so the weight trend is easier to interpret.
Judge the weekly trend
Daily weight changes reflect water, sodium, carbohydrate and digestion. Compare weekly averages and adjust only when the trend has been stable for at least two weeks.
Protect adherence and health
Persistent fatigue, dizziness, binge urges, menstrual changes or declining training performance suggest the plan may be too aggressive or needs professional review.
Sources & references
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247.
- Hall KD, et al. Energy balance and its components: implications for body weight regulation. Am J Clin Nutr. 2012;95(4):989–994.